Will the magnetism of neodymium iron boron magnets disappear? For all magnetic materials, they do not have magnetism at any temperature. Generally, magnetic materials have a critical temperature Tc. Above this temperature, the arrangement of atomic magnetic moments is disordered due to the violent Thermal motion of atoms at high temperature. Below this temperature, the atomic magnetic moments are arranged in order to produce Spontaneous magnetization, and the object becomes ferromagnetic.

How can the magnetism of neodymium iron boron magnets disappear? By utilizing this feature, many control components have been developed. For example, the rice cooker we use takes advantage of the Curie temperature of magnetic materials. A neodymium iron boron magnet and a magnetic material with a Curie temperature of 105 degrees are installed at the bottom center of the rice cooker. When the water in the pot dries, the temperature of the food will rise from 100 degrees. When the temperature reaches about 105 degrees, due to the disappearance of the magnetism of the magnetic material absorbed by the neodymium iron boron magnet, the neodymium iron boron magnet loses its attraction to it. At this time, the spring between the neodymium iron boron magnet and the magnetic material separates them, and drives the power switch to be disconnected to stop heating.

Curie temperature refers to the temperature at which a material can change between ferromagnets and paramagnets. When the material is below the Curie temperature, it becomes a ferromagnet, and the magnetic field related to the material is difficult to change at this time. When the temperature is higher than the Curie temperature, the substance becomes a paramagnet, and the magnetic field of the magnet is easily changed with changes in the surrounding magnetic field. At this point, the magnetic sensitivity is approximately 10 to the negative 6th power.